Open chamber gun



ec. 23, i958 D. DARDICK 2,865,26

OPEN CHAMBER GUN Filed sept. :5, 1954 IN VEN TOR. 9A iff/0 @ARD/CK @27% MMM A;

OPEN CHAMBER GUN David Dartlick, Greenwich, Conn., assignor to Dardick Corporation, a corporation of Delaware Application September 3, 1954, Serial No. 454,045

12 Claims. (Cl. t2- 60) This invention relates to rotary chamber portable tirearms, that is rotary chamber small arms and relates more particularly to open rotary chamber small arms of utility especially as hand guns, and to ammunition therefor.

It is an object of this invention to provide a new and improved open rotary chamber small arm of utility especially as a hand gun.

It is another object of this invention to provide a new and improved cartridge for open rotary chamber tirearms.

lt is another object of this invention to provide a new and improved open rotary chamber small arm which, for a given calibre, will be of lighter weight, greater simplicity and ammunition capacity, and can be manufactured at a lower cost, than like-calibre open rotary chamber small arms heretofore known.

It is another object of this invention to enable a substantial reduction to be effected in the number of moving parts, particularly reciprocating parts, required for the loading, firing, and ejecting of ammunition in a magazine-fed pistol.

It is still another object of this invention to combine the cylinder of a revolver with a separate ammunition magazine in such fashion as to provide a self-contained magazine-fed revolver.

It is a further object of this invention to enable a round of ammunition to be transferred automatically from a magazine into the cylinder of a revolver, without axial movement of the round.

It is a still further object of this invention to make possible the use of the handle of a revolver as an ammunition magazine from which a round of ammunition can be transferred automatically into the cylinder of the revolver upon each actuation of the trigger.

It is yet another object of this invention to provide a cartridge for an open rotary chamber gun which will be substantially proof against rupture longitudinally of the case and can be manufactured at a lower cost and with the use of less costly materials than has heretofore been deemed feasible or practical.

Other and further objects and advantages of this in vention will appear from the following description, the accompanying drawings and the appended claims.

According to this invention, there is provided an open rotary chamber gun wherein a rotary drum of initially cylindrical contour is mounted for rotation on its cylinder axis in a strong and rigid frame. The cylinder surface of the drum is radially depressed over a portion of its area to provide one, and preferably more than one, trough-like recess parallel to the rotational axis of the drum. The recesses are identical in shape, being of uniform noncircular contour from end to end in parallel planes normal to the rotational axis of the drum and tapered in Width in said normal planes from a maximum at the mouth of the chamber to a minimum at the base thereof. Each recess constitutes an open cartridge chamber through the open top of which the correspondingly shaped noncircular telescoped cartridge of this invention is adapted 2,865,126 Patented Dec. 23, 1958 to be inserted radially of the drum and to be seated longitudinally of the chamber.

The side walls of each such open chamber converge from top to bottom and may be fiat but are preferably uniformly curved in parallel planes normal to the rota tional axis of the drum, to the same radius of curvature as the cylinder surface of the drum.

Each chamber runs from one to the other of a pair of parallel planes normal to the rotational axis of the drum and marking, respectively, the barrel end and the primer end of the chamber. The rotary drum is con. sti-acted and arranged to provide an escape opening at the barrel end of the chamber through which the bulletV or projectile of a cartridge seated within the chamber, may be discharged into the bore of a barrel of the gun in alignment therewith. Likewise, the rotary drum is constructed and arranged to provide an access opening at the primer end of the chamber through which a tiring pin or other suitable firing means may be caused to act on the primer of the cartridge, to tire the same.

In accordance with a preferred construction, each chamber runs from end to end of the drum, the access and escape openings of the chamber being located in opposite end faces of the drum and being of the same size and shape as the chamber in cross section.

The open chambers of the drum are disposed in uniformly spaced relation to each other around the circumference of the drum. Thus, for each revolution of the drum, each chamber will travel once around the rotational axis of the drum in a closed circular path. This path, starting from a loading position passes successively through a firing or battery position and an ejecting position, and thence to the loading position again, to complete the cycle. Each chamber, while in transit through the loading position, is Vradially supplied automatically with a round of ammunition from a magazine unit which is preferably detachably connected to, and forms a handle of, the gun.

The magazine unit is constructed and arranged to provide an ammunition storage chamber within its confines, the magazine unit being open at one end and being designed to receive, at the opposite end, a load of ammunition. The ammunition load is arranged in the storage chamber in one or more rows of side-by-side rounds, the rounds being delivered successively through the open end of the magazine unit to successive cartridge chambers of the rotary open chamber drum as it rotates.

The open chamber rotary drum `serves as a rotary gating and conveying device functioning in rotation to pick-off one round of ammunition at a time from the magazine unit and to convey the round sequentially to the battery position for ring and thence to the ejecting position for ejection from the drum. In the latter position, the empty cartridge case is automatically ejected from the chamber by suitable ejecting means projected into the chamber at a suitable phase of the cycle.

The drum is suitably disposed at the open end of the magazine unit to bring the open chambers of the drum successively into opposition with a terminal round of ammunition in the opening, as the drum is rotated. To this same end, means are provided at the opposite end of the magazine unit for yieldably urging the row or rows of ammunition in the stationary magazine chamber toward and into contact with the cylinder surface of the rotary drum so that the terminal round of ammunition in a given row will be caused to enter and be seated in the first empty open chamber brought into opposition therewith.

The stationary frame of the gun is constructed and arranged to serve as a breech for both the open top and the primer end of each cartridge chamber, when the chamber is in battery position. To this end, the framev is3 of a configuration to provide longitudinally of the drum axis a breech surface of cylindrical contour which is concentric with the drum and is suitably dimensioned in directions normal to and longitudinally of the rotational axisof the drum, to span the openchamber from side-ltojside and from end-to-end, when the chamber is in'v battery position.

The arcuate breech surface has a radius of curvature only slightly larger than that of the drum so that the cylinder surfaces of the drum and breech will be in substantially Vwiping engagement when in opposing relation to each other. Thus, each open chamber on reaching its battery position will be completely capped by the arcuate breech surface and thus be converted into a closed. cartridge chamber of generally triangular shape o ering a substantially continuous supporting wall surfaceagainst which the cartridge case may expand.

`For the'purpose of closing the primer end of the open cartridge chamber in battery position, the frame of the gun isalso constructed and arranged to provide, normal to the drum axis, a breech"VY surface disposed to lie in opposing closely spaced relation to the primer or butt end of the drum so as to be in substantially wiping engagement therewith. This latter brech surface, like the cylindrical breech surface, is suitably dimensioned to span the recess from side-to-side and from top to bottom thereby to provide a surface against which the primer end of the cartridge may expand and press When tired.

Trigger-actuated means are provided for effecting rotation of the rotary drum so as to bring the successive recesses into battery position and for tiring the individual roundsv when so positioned.

In accordance' with this invention also, there is provided a cartridge for use with the open chamberV gun of this invention wherein the bullet `or projectile of the cartridge, together With the propellant therefor, is wholly contained within the case or shell of the cartridge.

llxteriorl'y, the case is of a contour which is other than circular, and, in its more specific aspects, is of a contour, s to part of its circumference, matching that of the recess of the open chamber gun of this invention in which it is to be seated. As to the remaining part, it is of cylindrical contour matching that of the cylinder surface of the drum. Thus, when positioned in an open chamber of the gun, the cartridge will t snugly against and be supported by the walls of the chamber. Moreover, because of its cylindrical surface portion it serves to provide, in effect, a continuation of the cylinder surface of thedrum over the entire span of the chamber at its mouth. Preferably, the case is of triangular shape, each of its sides being arcuate and of equal radius` of ycurvature so that when used in an open chamber whose sides are correspondingly curved, it may be inserted in the chamber withany one of its three apices at the bottom ofthe chamber. l

Interiorly, the case is of a contour circumferentially which also is other than circular so that the gas pressure createdv within the case on firing will tend to cause the case to assume a circular shape and thusvtol be firmly supported externally throughout its entire circumferential periphery by the walls of the open chamber and by the arcuate bre'ech surface of the gun frame. Advantageously, the internal contour of the case may be geometrically similar to its external contour, since the fabrication of the case is facilitated in so doing andthe wall thicknesses of the case may be lclosely controlled within permissible limits. In accordance with this invention, moreover, the thickness of the case is preferably greater at the intersections of the case walls than between the intersections. In this way, reinforcement is provided at the corners of the case so that the possibility of thercase bursting longitudinally along the line of either joint between the rotary drumand cylindrical breech surface of the giuri, is completely, or substantially completely, eliminate The casing is of a length coextensive with that of the open chamber in which it is to be used. One of its ends; the primer end, is closed by a primer unit which, in battery position of the open chamber, is adapted on tiring of the cartridge to press against and be opposed by the end breech surface of the gun frame.

Means are provided within the case for supporting the bullet of the cartridge wholly within the case in annularly spaced relation thereto, and for forming a sealing ange at the other end, the muzzle end, of the case. The supporting and flange-forming means as embodied comprises an imperforated sleeve preferably of cylindrical contour, disposed centrally and longitudinally of the case in annular spaced relation thereto, the sleeve being hermetically sealed to the case at its outer end and forming an annular obturating flange thereat. The sleeve telescopically receives, and securely but releasably holds, the bullet in coaxial alignment therewith, in position to be propelled axially from the case into the bore ofl the gun barrel. The interior of the case, including the annular space betweenY the sleeveV and the case, contains the propellant. Advantageously, the sleeve may be ried internally, if desired, for co-action with a rotating band on the bullet. In such case, the rifiing or pre-engraving of the sleeve or bullet should conform in pattern to that of the rifling of the barrel of the gun with which the cartridge is to be used, it being apparent that the cartridge must be properly indexed in its recess to achieve alignment of the rifling of cartridge and barrel. To this end, the cartridge and the open chamber of the gun'in which it is to be Vemployed may be of a contour such that the cartridge may be received, or pre-indexed, in the chamber in only one position. It will be understood that since the annular space between the case and sleeve is closed at its outer end by a connecting annular obturating Wall portion, the expanding gases in the cartridge on firing will tend to force the connecting obturating wall into iirm sealing engagement With the breech end of the gun barrel, thus effectively preventing escape of the propellant gases during and after passage of the bullet through the escape opening of the recess or open chamber.

In the accompanyingv drawings which form part of the instant specication and in which like numbers refer t0 like parts throughout the several views,

Fig. l is a view in side elevation with parts in section 0f a typical and illustrative embodiment of a magazine-fed, open chamber revolver in accordance with this invention, the view showing the magazine and open chamber of the revolver loaded with the new and improved non-circular, telescoped cartridge of this invention, the rotary chamber being shown in battery position;

Fig. 2 is a view n'section taken along the line 2-2 0f Fig. l showing the arrangement of the cartridges in parallel rows in the magazine handle of the revolver;

Fig. 3 is a fragmentary view in section taken along the line `3 3 of Fig. l showing the rotary chamber revolved from the battery position shown in Fig. l to the cartridge' ejecting position; y Y

Fig. 4 isa somewhat enlarged fragmentary view in section taken along the line 4 4 of Fig. l, the view showing details of the cartridge construction; and

Fig. 5 is a fragmentary isometric view of the open chamber revolver of Fig. 1 showing details of the open chamber. e

Referring now more particularly ,to the accompanying drawing, a rotary drumv 1 is mounted for rotation on its cylinder axis in a frame 2 by means of coaxially aligned shafts 3 and,4 at its respective opposite ends.4 The drum is recessed longitudinally' to provide a plurality'of cpen chambers 5 which, as hereipreferably embodied, are three in` number and are spaced at equal distances circumferentially around the drum. l

VThe chambers 5 are' identical and parallel the rotav tional axis of the drum. The side walls 6 of each chamber are arcuate in shape, each having a radius of curvature the same as that of the drum. Thus, each chamber is adapted to receive within its contines a cartridge in accordance with this invention having a configuration precisely conforming to that of the chamber. Moreover, each chamber extends from one end to the other of the drum so as to provide an escape opening 7 at one end of the drum and a primer opening 8 at the opposite end of the drum.

As shown in Figs. l and 2 the drum is in battery position in which the topmost chamber of the three chambers in the drum is aligned with a barrel 9 carried by the frame 2. In this position, the geometrically longitudinal axis of the chamber is coaxially aligned with the axis of the bore 10 of the barrel.

The frame 2 forms a breech for the open top of the primer opening 8 of the chamber when the latter is in battery position. To this end, the frame 2 is provided with a cylindrical breech surface 11 which as shown in Fig. l spans the chamber from end to end and, as shown in Fig. 2 spans the chamber between the Walls 6 and, preferably, is dimensioned to overlap the walls 6 so as completely to close the open top or mouth of the chamber. The cylindrical breech surface 11 is concentric with the rotational axis of the drum 1 and is of a radius of curvature which is substantially the same as that of the cylinder surface of the drum. Thus, as the drum is rotated, its cylinder surface and the cylindrical breech surface 11 will be in substantially wiping engagement with each other. Moreover, as is best seen in Fig. 4, the cartridge 12 with which the chamber 5 is loaded, is, like the chamber, of non-circular configuration externally matching that of the chamber. The walls 13 of the cartridge are, as shown, arcuate in shape and of a radius of curvature the same as that of the drum 1. Thus, when the cartridge is positioned in the chamber, the uppermost wall of the cartridge forms a continuation of the cylindrical surface of the drum so that the drum is capable of rotating freely with respect to the cylindrical breech surface 13 of the frame 2. Moreover, since each of the walls 13 of the cartridge are of the same curvature, the cartridge may be inserted in the chamber 5 with any one of its sides uppermost so that indexing of the cartridge with respect to the chamber during the loading operation, is unnecessary.

Closure of the primer end c-f the chamber 5 in the battery position is effected by a dat breech surface 14 which is normal to the rotational axis of the drum 1 and is in closely spaced parallel relation to the breech end surface 15 of the drum. Thus, the breech surface 14 provides a strong and rigid supporting surface against which the primer end of the cartridge 12 is adapted to bear when I the cartridge is fired.

The frame 2 also serves to support a firing pin 16 and a hammer 17 which latter is actuated by suitable trigger mechanism including trigger 18 and hammer-actuating shaft 19.

The shaft 19 vis recipro-cably mounted in the frame 2, being connected at its one end to the hammer 17 by means of a pin 2@ which rides in a slot 21 in the hammer. The opposite end of the shaft 19 is bifurcated to receive within the yoke thereby formed, one end of the trigger 18 which latter is provided with an arcuate slot 22 which receives a pin 23 so that rearward movement of the trigger on its trigger pin 24 will effect a forward movement of the hammer-actuating shaft 19 and, in turn, movement of the hammer to a cocked position as shown in Fig. 1. The shaft 19 carries a hammer spring 25 concentric therewith tending to drive the head 26 of the hammer against the firing pin 16. t

Means are provided for effecting rotation of the drum 1 so as successively to bring the chambers S each to the battery position during cockirig of the hammer 17, and to lock the drum in battery position as the hammer falls. As here preferably embodied, the drum shaft or axle 4 which is journalled in the frame 2 is provided at its forward end with a cylinder cam 27 having a number of camming surfaces 28 disposed longitudinally and circumferentially thereof, there being one such camming surface for each of the chambers of the drum. A cam actuating lever 29 is pivotally slidably mounted on a pin 30 carried by the frame 2 so as to engage the camming surfaces 28 one at a time and to rotate the cylinder cam 27 and thus the drum 1 through a 120 angle of rotation for each full rearward movement of the trigger 18. The lever 29 terminates at its one end in a cam actuating surface 31 engaging the cam surface 28 as shown in Fig. 1, and terminates at its opposite end in a slot 32 receiving the pin 23 carried by the trigger 18. The lever 29 is also slotted intermediate its ends as at 33 Vfor theY reception of the pivot pin 30 in order that angular movement of the lever on the pin 30 may be accompanied by lengthwise movement of the lever on the pins 30 and 23. Clockwise movement of the lever 29 as viewed in Fig. l is opposed by a return spring 34 carried by the frame 2 so that as the cam actuating surface 31 of the lever escapes from the cam surface 2S, the lever will be snapped back to its starting position in engagement with the left hand end of the next succeeding cam surface 28.

Means are provided for locking the drum 1 against rotation in the cocked posi/tion of the hammer as shown in Fig. 1. The locking means comprises a detent 35 pivotally mounted on a pin 36 carried by the frame 2, the detent being urged into locking position in a recess 37 in the drum 1 by a spring 38 carried by the frame 2. One such recess is provided for each of the chambers 5 in the plane of symmetry of the chamber in the battery position. The detent 35 includes a scar 39 which is pivotally mounted as at 40 on the detent and is adapted to be engaged by an actuating pin 41 of a pinion 42 which, in turn, operatively engages a rack 43 on the hammer-actuating shaft 19. As will be apparent from Fig. l, with the parts in the position there shown, the drum 1 is locked against rotation by the detent 35. Further rearward movement of the trigger 18 from the position shown will cause the cam actuating lever 29 to escape from the cam surface 31 thereby releasing the hammer so that it will strike the firing pin 16. In this operation the hammeractuating shaft 19 moves to the right as viewed in Fig. l

under the action of the spring 25, rotating the pinion 42 in a counterclockwise direction so that the pinion pin 41 engages the sear 39 and displaces it on its pivot pin 40. The detent will remain in locked position in the recess 37. Then, at the inception of the next rearward movement of the trigger, the pinion pin 41 will engage the sear 39 to rotate the detent 35 in a counterclockwise direction against the action of the spring 38 and thus free the detent from the recess 37. The drum is now free to be rotated by the cam 27 driven by the lever 29, this rotation continuing until the next chamber is brought into battery position, at which time, the pinion pin 41 escapes from the sear 39 permitting the spring 38 to move the detent into the related recess 37 in this succeeding battery position.

A magazine unit 46 is detachably connected to the frame 2, the unit forming a handle for the gun and its interior providing a chamber 47 partitioned centrally between its side walls by a partition member 48 to provide right-hand and left-hand compartments adapted each to contain a vertical row of cartridges in side by side relation. The magazine unit is open at its top and is detachably connected to the frame 2 by a bifurcated clamp 49 at the top of the partition member 48, the clamp having oppositely depressed clamping flanges 50 seated in grooves 51 in the frame 2. By this arrangement the magazine unit can be readily detached for loading with ammunition. As will be seen from Fig. 2, the right-hand and left-hand compartments 52 and 53, respectively, of the magazine unit are open at the top so that the topmost round of the row of ammunition in either compartment is adapted to enter the first empty chamber of the drum 1 which comes 1n opposition to the topmost round. Means are provided for forcing the topmost round into the empty chamber and as here preferably embodied each of the chambers is provided with a spring pressed follower as at 54 and 55 respectively. The follower 54,V for example, presses against the bottommost round of the row of ammunition in the chamber 52 thus urging the topmost round into sliding contact with the cylindrical surface of the drum 1.

In Fig. 3 the drum 1 is shown in cartridge ejecting posi4 tion after having been rotated from the battery position shown in Fig. 2. Thus, the right-hand chamber 5 is empty and, when the drum is further rotated the empty chamber will be brought into position With the topmost round in the chamber 52, the round then being forced into and seated in the chamber by the action of the spring pressed follower 54 at the bottom of the chamber. It will'be apparent that so long as the empty chamber is loaded with ammunition from the right-hand compartment 52, no ammunition will be transferred from the left-hand chamber 53 into the drum. However, so soon as the right-hand chamber is empty, feeding of the ammunition from the left-hand chamber into the empty drum chamber will commence. Moreover, since each cartridge is of generally equilateral triangular configuration, each cartridge in the row in the respective chambers 52 and 53 can enter the empty chamber in the drum regardless of the arrangement of the cartridges in the magazine unit. It will be apparent that the rotary drum 1 positioned at the open top of the magazine unit serves as a gating and conveying device for preventing the escape of ammunition from the magazine unit and for picking off the topmost round of the row of ammunition for conveyance to the battery position.

Means are provided for ejecting the empty cartridge case from the chamber 5 after firing. As here preferably embodied, the drum 1 is slotted radially at the bottom of each of the chambers 5 so as to provide thereat a slot Y 56 within which is pivotally mounted an ejecting lever 57 in such fashion as to bear upon but not press against the opposing longitudinal apices of the cartridge 12 when the latter is positioned in the chamber. The lever 57 extends beyond the end of the drum 1 into a well 58 in the frame 2, the well 58 being generally concentric with the drum shaft 3 but having a camming surface 59 (Fig. 3) extending inwardly toward the drum shaft 3. The camming surface 59 is of a configuration suitable to depress the projecting end of the ejecting lever 57 as the drum is rotated by the trigger mechanism from the battery position shown in Fig. 2 to the ejecting position shown in Fig. 3, thereby to propel the empty case of the cartridge 12 out of the chamber 5 of the drum as is indicated by the dotted line cartridgeshown in Fig. 3. lCompletion of the triggermovement brings the empty chamber into the loading position at the open top of the magazine unit, as has been described above. n

As has also been described above, the cartridge 12 is of non-circular contour externally and is received in the non-circular chamber 5 of the drum, the chamber being capped or closed in the battery `position by the cylindrical breech surface 11. It will therefore be apparent that the cylindrical breech surface 11 and the walls 6 of the open chamber 5 together form a closed chamber for the cartridge 12 in the battery position. The walls of this closed chamber are substantially continuous except for the joints at the opposite sides of the mouth of the chamber 5 where the walls 6 of the chamber abut the cylindrical breech surface 11.

Interiorly, the cartridge 12 is also of non-circular contour so that the expansion of gas within the cartridge on tiring will tend to cause the arcuate walls 13 of the cartridge to take a circular contour. In so doing each wall 13 is thereby firmly supported throughout its whole'v circumferential area by either the walls 6 of the open chamber 5 or the cylindrical breech surface 11 of the frame 2. The cartridge walls 13 are reinforced at their intersections with each other so that at the joints of the closed chamber formed by the drum 1 and the frame 2 in battery position, the cartridge case will be suflciently strengthened to ensure against any possibility of longitudinal bursting of the Icase at the joints under the pressure of the expanding gases.

Means are provided within the cartridge case formed by the arcuate walls 13 for supporting a' projectile or bullet 60 of cylindrical contour wholly within the interior of the cartridge case and with its axis of revolution in alignment with the axisof the bore 10 of the barrel 9,

and for forming an obturating flange at the muzzle end ot' the cartridge case adapted to seal hermetically the joint between the cartridge case and the breech end of the gun barrel 9. To this end, a cylindrical sleeve 61 jackets the bullet 60 and terminates at its one end in an annular radially extending flange portion 62 whose outer circumferential periphery is of a configuration matching that of the interior of the case formed by the cartridge walls 13. Advantageously, this flange portion 62 may be formed with a reentrant skirt portion 63 serving to extend the available surface area for joining the flange portion 62 to the walls 13 of the cartridge case.

A primer unit 64 is positioned at and closes the other end of the cartridge case 13, the unit 64 in turn being provided with a primer 65 in coaxial alignment with the longitudinal axis of the bullet 60.

It will be apparent from the foregoing that the bullet sleeve 61 is in annularly spaced relation to the Walls 13 of the cartridge so that the pressure of expanding gases within the cartridge will be exerted within this annular space 66 against the annular flange portion 62 which in battery position, abuts the breech end 67 of the barrel 9 and thus effectively seals the joint therebetween when the cartridge is fired.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention.

What is claimed is: Y

1. An open chamber gun ycomprising a drum of cylindrical contour mounted for rotation on its cylinder axis, said'drum having at least one open chamber in its cylinder surface for conveying a cartridge seated therein from a loading position to a battery or firing position and thence to an ejecting position, each said chamber paralleling the cylinder axis of said drum, being of uniform noncircular shape from end-to-end inparallel planes normal to saidv cylinder axis, and having, at its respective opposite ends, an access opening and an escape opening; a breech frame in which said drum is mounted for rotation, said frame having an arcuate breech surface concentric and substantially co-equal in radius of curvature with the arcuate surface of said drum, for closing off the open top of said chamber in said battery position and having a separate breech surface for closing off the access opening of said chamber in the same position; a gun barrel with which said chamber is aligned in said battery position; and, a magazine unit havinga chamber therein for storing ammunition' for said rotary drum in a row of side-by-side rounds between opposite ends of said storage chamber, having a transfer opening at the one end of said storage chamber located in juxtaposed relation to and closed by the arcuate surface of said drum, through which opening the terminal round of ammunition at the corresponding end of said row is movable radially of said drum through the open mouth of and into ank empty cartridge chamber of said drum, in the loading position of said chamber, and having means in said storage chamber at the other end thereof for acting on the corresponding end of said row of ammunition to press said terminal round into sliding contact with the cylinder surface of said drum at said transfer opening.

2. An open chamber gun comprising a drum of cylindrical shape mounted for rotation on its cylinder axis, the cylindrical surface of the drum being depressed over a portion of its area to provide a plurality of open chambers therein equally circumferentially spaced from each other for conveying successive rounds of ammunition in a closed circular path from a magazine to a battery or tiring position and thence to an ejecting position, said chambers extending from end-to-end of said drum parallel to said cylinder axis, being symmetrical about a plane of the cylinder axis of said drum and being of identical uniform non-circular shape from end to end in parallel planes normal to said cylinder axis, the side walls of the respective chambers converging from top to bottom and being arcuate surfaces having a radius of curvature the same as that of the cylindrical surface of said drum; a breech frame in which said drum is mounted for rotation, said frame having a cylindrical breech surface substantially co-equal in radius of curvature with the cylindrical surface of said drum, for closing olf the open top of each said chamber in said battery position, and having a separate breech surface normal to said cylinder axis in closely spaced parallel relation to one end of said drum for closing otf the corresponding end of the respective chambers in the same position; cam-actuated means carried by said drum for radially ejecting empty cartridge cases from the respective chambers in said ejecting position; cam means carried by said frame for actuating said ejecting means in rotation of said drum; a gun barrel with which each said chamber is aligned in said battery position; and, a magazine unit having a chamber therein for storing ammunition for said drum in a row of sideby side rounds between opposite ends of said storage chamber, having a transfer opening at the one end of said storage chamber for the movement of the terminal round of ammunition at the corresponding end of said row into each said open chamber in the loading position thereof, and having means in said storage chamber at the other end thereof for acting on the corresponding end of said row of ammunition to press said terminal round into sliding contact with the cylindrical surface of said drum at said transfer opening.

3. An open chamber gun in accordance with claim 2 including trigger-actuated means for rotating said drum.

4. An open chamber gun in accordance with claim 3 wherein said rotating means comprises a cam carried by said drum and a spring-pressed cam-actuating lever pivotally mounted on said frame.

5. An open chamber gun in accordance with claim 2 in which said cam-actuated ejecting means comprises as to each such open chamber a lever pivotally mounted on said drum at the bottom of said chamber and wherein said frame is provided with a well concentric with the axis of said drum into which the individual levers of said drum extend, said well having a camming surface for actuating said levers in a determined position of said drum.

6. An open chamber gun in accordance with claim 2 in which one end of said drum and the breech end of said barrel are in closely spaced parallel relation to each other.

7. An open chamber gun in accordance with claim 2 in which said magazine unit comprises a partition dividing said storage chamber from end to end into separate compartments for the reception in each of a row of sideby-side rounds of ammunition, the rows parallelling each other, said magazine unit having an opening at each of the pair of corresponding ends of said compartments for the transfer of the terminal rounds of ammunition in said rows to successive open chambers of said drum, said drum being disposed and arranged at the open ends of said compartments for the reception of ammunition from either of said rows into an empty open chamber brought into loading position relative to either of said transfer openings.

8. An open chamber hand gun in accordance with claim 2 in which said magazine unit is releasably mounted on said frame and forms a hand grip for the gun.

9. In a revolver, a cylinder having cartridge chambers and in which the cartridge chambers are in the form of radial depressions in the arcuate surface of the cylinder and have each an open top and open ends, and a handle in which the parts thereof are constructed and arranged to provide a magazine unit having a chamber for the storage of ammunition for said cylinder in a row of si-de-by-side rounds between opposite ends of said storage chamber, said Vmagazine unit having at one end of said storage chamber a transfer opening located in juxtaposed relation to and closed by said arcuate cylinder surface, through which opening the terminal round of ammunition at the corresponding end of said row is movable radially of said cylinder through the open mouth of and into an empty cartridge chamber of said cylinder in alignment therewith, said cylinder serving as a rotary gating device for said opening, and said magazine unit having spring-pressed means at the opposite end of said storage chamber for acting on the corresponding end of said row to press said terminal round into sliding engagement with the arcuate surface of said cylinder at said transfer opening.

l0. An open chamber gun comprising a drum of cylindrical shape mounted for rotation on its cylinder axis, the cylindrical surface of the drum being radially depressed over a portion of its area to provide a plurality of open-top ammunition chambers therein equally circumferentially spaced from each other for conveying successive rounds of ammunition in a closed circular path from a magazine to a battery or tiring position and thence to an ejecting position, said chambers extending from end-to-end of said drum parallel to said cylinder axis, being symmetrical about a plane of the cylinder axis of said drum and being of identical uniform non-circular shape from end to end in parallel planes normal to said cylinder axis, the side walls of the respective chambers converging from top to bottom and being arcuate surfaces having a radius of curvature the same as that of the cylindrical surface of said drum; a breech frame in which said drum is mounted for rotation, said frame having a cylindrical breech surface concentric and substantially co-equal in radius of curvature with the cylindrical surface of said drum, for closing olf the open top of each said chamber in said battery position, and having a separate breech surface normal to said cylinder axis in closely spaced parallel relation to one end of said drum for closing off the end of the respective chambers at the same end of said drum, in said battery position; means for radially ejecting said rounds of ammunition from the respective chambers in said ejecting position; a gun barrel with which each said chamber is aligned in said battery position; and, a magazine unit having a chamber therein for storing ammunition for said drum in a row of side-by-side rounds between opposite ends of said storage chamber, having a transfer opening at the one end of said storage chamber located in juxtaposed relation to and closed by the arcuate surface of said drum, through which opening the terminal round of ammunition at the corresponding endof said row is movable radially of said drum through the open mouth of and into each said open chamber in the loading position thereof, and having means in said storage chamber at the other end thereof for acting on the corresponding end of said row of ammunition to press said terminal round into sliding contact with the cylindrical surface of said drum at said transfer opening.

l1. An open chamber gun comprising an ammunition drum of cylindrical contour mounted for angular movement on its cylinder axis, the arcuate surface of said drum being radially depressed over a portion of its area to provide at least one open-top ammunition chamber in its cylinder surface for conveying a round of ammounition seated therein from a loading position to a battery or ring position and thence to an ejecting position, each said chamber paralleling the cylinder axis of said drum, being symmetrical about a plane of the cylinder axis of said drum, being of uniform non-circular shape from end to end in parallel planes normal to said cylinder axis and tapered in width in said normal planes from a maximum at the mouth of the chamber to a minimum at the base thereof, and having, at its respective opposite ends, an access opening and an escape opening; a breech frame in which said drum is mounted for rotation, said frame having an arcuate breech surface concentric and susbtantially coequal in radius of curvature with the arcuate surface of said drum, for closing off the open topn of said chamber in said battery position so as to convert said open chamber in said position into a closed chamber of generally triangular conguration,

12 and having a separate breech surface" for closing 0E the access opening of said chamber in the same position; and, a gun barrel with which said chamber is aligned in said battery position.

12. An open chamber gun according to claimVIA 1'1 `in which the side walls of the respective chambers converge from top to bottom and are arcuate surfaces having a radius of curvature the same as that of the cylindrical surface of said drum.

References Cited in the le of thispatent UNITED STATES PATENTS 35,996 Doolittle July 29, 1862 378,091 Greth Feb. 21, 1888 467,089 Forbes Ian. 12, 1892 650,461 Haws May 29, 1900Y 696,539 Bennett Apr. 1, 1902 1,109,840 Hoagland Sept. 8, 1914 1,227,439 Hilgendorf May 22, 1917 2,353,934 Schreib July 18, 1944 

